Solution to session variable access after hyperlink

Access test2.php: & lt ;? Phpsession_start (); if (! Isset ($ _ session ['card ']) echo & quot; die & quot; $ _ session ['card'] = & session variable access after hyperlink
Test2.php:
Session_start ();

If (! Isset ($ _ session ['card '])
Echo "die ";
$ _ Session ['card '] = "123 ";
?>


Test webpage 2


Echo $ _ session ['card '];
?>

3






Test3.php:
Session_start ();
Echo $ _ session ['card '];
?>
Why is the session variable inaccessible after the hyperlink?

------ Solution --------------------
$ _ SESSION ['card '] = "123"; // uppercase

Test3.php:
Session_start ();
Echo $ _ SESSION ['card '];
?>

------ Solution --------------------
Why not? Is the test2.php page output 123?